The Internet of Things (“IOT”) is a recent development in which everyday objects have connectivity to data networks allowing them to send and receive data to other devices or systems. The connectivity enables the devices to achieve greater value and service by exchanging data with other systems, servers and controllers. Sometimes this connectivity is used for remotely monitoring and controlling the connected device. IOT systems generally refer to the integrated use of telecommunications devices in embedded systems for transmitting, receiving, controlling, remotely storing and processing information. More generally, IOT may refer to smart devices sending, receiving, and storing information via telecommunication devices over a public communication network such as the World Wide Web (“WWW”).
Other than the convergence of telecommunications and information processing, the term IOT may also refer to automation of various processes relating to the controlling and managing remote devices and systems. For example, in a scenario where an IOT system includes multiple food or beverage vending machines, the IOT system can report the inventory status of remote vending machines, operate e-payment systems that facilitate purchase of items from the vending machine, update content to be displayed on the exterior of one of IOT vending machines, and report interior temperature of one or more of the vending machines to provide an enhanced experience for the customers. In another scenario, an IOT system can allow a homeowner to remotely monitor and control the heating and air conditioning systems utilizing a smart thermostat while communicating over a communication network with one or more centralized servers manage intelligent energy efficiency and to process consolidated energy usage reports. This IOT system may also synchronize the energy usage with other nearby systems to smooth out localized energy usage peaks, lowering overall peak energy demand on public utilities such as electricity and natural gas. In other aspects, the homeowners IOT system may monitor weather conditions and synchronize water usage for non-essential activities such as pool water replenishment and landscape watering.
An IOT device may be connected to a larger network, usually the Internet using an ever-expanding number of methods. Early connected devices were networked with each other using proprietary localized networks created using multi-drop serial networks or simple non-standardized wireless networks. Those devices generally communicated with local gateways or controllers and were rarely remotely operable. As wide area networks were established, creative ideas drove the concept of connecting and controlling devices beyond the reach of the local network. As new technologies drive down costs of embedded electronics, sensors, and network connectivity, interconnection of devices and systems becomes more common.
Another major development that has contributed to the expansion of the IOT is the widespread rollout of centralized “cloud computing” services. Cloud computing allows application software to be operated using centralized, sometimes virtualized, Internet connected services. The foundation of cloud computing is based on the broader concept of shared services and a converged infrastructure. Cloud computing, which some may generally refer to as ‘the cloud,’ relies on the sharing of resources and the economies of scale to deliver services. Combining the capabilities of the low cost, emerging, and connected smart devices with the expanse of connected cloud computing environments has created a technological opportunity to develop innovative solutions that will enhance automation in nearly every aspect of life.
Early Internet connected devices required complicated and expensive gateways to establish the Internet Protocol (“IP”) connectivity. In the early days of the IOT, Ethernet, the primary physical connectivity medium, required expensive and power hungry hardware. The software stacks to implement IP were large and complicated and not easily ported to hardware systems unless the hardware included significant processing power and memory. Many of those IP stacks required an advanced operating system that further drove the hardware complexity. Over the last few years, micro computing and memory technologies have advanced to the point where a full operating system can be ported to very small and cost effective platforms. Some of the new single-chip micro computing platforms that have been introduced over the last five years are powerful enough to include an IP stack, real-time operating system and sensor management to support an advanced smart device.
Advances in the various physical layer communication devices and technologies have also encouraged the deployment of connected devices. For example, Wi-Fi is a wireless local area network (“WLAN”) computer networking technology that allows electronic devices to connect directly to the Internet thru a Wi-Fi wireless access point (“WAP”). Wi-Fi networks typically operate using low power transmitters on unlicensed spectrum at either 2.4 GHz or 5 GHz. The specifications for Wi-Fi networks are based upon IEEE 802.11 standards. Although the name “IOT” infers a direct connection to the Internet, in many cases the direct connection is using a medium and technology that is not directly IP. The reasons for selecting a different connection type are many.
Other recently developed technologies that are driving the IOT include ZigBee, Z-wave and of course the various Wireless Wide Area Network (“WWAN”) technologies such as GSM, UMTS, and LTE. WWAN technologies differ from WLAN technologies by using different spectrum, protocols, security and authentication systems and the coverage area of a WWAN is typically much larger. WWAN wireless networks are usually operated by mobile telecommunications (or cellular) operators using licensed spectrum. The services may be offered regionally, nationally or globally.
Devices connecting to the Internet using various WWAN technologies are older than the term “Internet of Things.” Early non-cellular technologies included Mobitex, DataTAC, and ReFLEX. Each was purpose-built data-networks that supported narrow-band two-way data connectivity. Although the networks existed before the wide acceptance of what we now know of as the Internet, they operated on private wide area networks. As the wireless cellular networks became more refined, systems emerged to leverage the assets of cellular operators. In the United States, Cellular Digital Packet Data (“CDPD”) networks were developed and deployed using the unused bandwidth of the AMPS analog mobile networks. While CDPD supported speeds up to 19.2K bits per second, and was significantly faster than Mobitex, DataTAC, or ReFLEX, it could not compete against the slower, less expensive and more flexible Mobitex, DataTAC, or ReFLEX networks.
Outside the US, GSM networks, a second-generation (“2G”) technology were being deployed using digital wireless technology, as opposed to the analog networks of AMPS. Being digital, the networks could inherently carry data communications but the connectivity was not usually to a wide area network like the Internet, but to local modem interworking-function platforms that placed an outgoing analog dial-up modem call over the fundamentally analog public switched telephone network (“PSTN”), bridging the digital GSM world with the analog PSTN world. This was called circuit-switched data (“CSD”). The over-arching premise of the CSD solutions depended upon on the mobile device initiating the outgoing connection.
The wireless networks in the United States began to deploy digital wireless technology, principally for voice, in more than a few markets by the mid- to late-1990's. These systems also included a modem interworking-function or CSD that depended on the mobile device to initiate the outgoing interconnection to its destination. As the Internet became popular in the late 1990's, the modems were removed from interworking-function, allowing the device to connect to the Internet directly without going thru an analog modem to the PSTN to reach the Internet. Again, it should be noted that these CSD-connected devices, which could perhaps be considered as the first IOT devices, could initiate outgoing data connections, but could not easily receive incoming data connections from the Internet.
In the early 2000's, the GSM operators began to deploy General Packet Radio Service (“GPRS”) technology in their wireless networks. GPRS is a packet oriented mobile data service for GSM 2G and third generation (“3G”) networks. Instead of “dialing” thru a CSD connection, GPRS devices access the terrestrial packet network using an access point name (“APN”), username and password. Although the APN may specify access to the public Internet, it may also specify access and connection to a defined endpoint, for example, to a private enterprise network. This was the first system to provide worldwide mobile access to the Internet. As above, it should be noted that these WWAN connected devices initiated the outgoing connection to the external packet networks.
The wireless industry refers to incoming wireless device connections, as mobile terminated (“MT”) voice or data connections. MT wireless devices and connections are considered mobile, without regard to the movability of the device. The significant advantage of the early packet data networks such as Mobitex, DataTAC, and ReFLEX was their ability to accept MT data connections. Mobitex, DataTAC, and ReFLEX networks were principally designed to support two-way paging-like features, including portable wireless devices carried on one's person like a one-way pager and as such, these networks supported devices that firstly supported incoming MT data. For the cellular wireless and GPRS networks, including Universal Mobile Telephone Service (“UMTS”) networks, data transport was an afterthought (or late addition) and receiving incoming data connections was not generally supported by the networks for the vast number of devices that operated or will operate on the wireless networks. Short Message Service (“SMS”) connectivity was one of the first types of MT data supported by the vast majority of wireless mobile devices that were created first and foremost for voice services.
The methods of receiving, accepting. and acting upon incoming data connections are many. Almost all current methods are very slow or very expensive in terms of network resources. One method currently used almost exclusively for IOT devices involves sending an SMS message to the remote wireless device and once received, the remote wireless device initiates an outgoing connection to the requesting server. Many people familiar with IOT and wireless networks know of this method as an ‘SMS Shoulder Tap.’ Another method supported by some IOT devices, but significantly less popular, is to place an MT voice call to the IOT device using its Mobile Station International Subscriber Directory Number (“MSISDN”). The data device does not accept the MT voice call, but instead uses this incoming call as a triggering event and subsequently initiates an outgoing IP connection to the requesting server. Both methods described are problematic and involve significant latency and require the initiating server to interface to disparate systems.
The GSM standards body, 3rd Generation Partnership Project (“3GPP”) did not totally ignore MT data connections. These groups have specified methods to establish incoming connections to a wireless device. These methods are fairly straightforward, but the industry never contemplated the massive number of wireless devices requiring incoming data connections that exist, or will exist, in today's IOT environment. The method established by 3GPP involves using a public (Internet) fixed IP address, either an IPv4 or IPv6 address, for each IOT device. Several problems that were not anticipated by the standards committees have challenged network operators when attempting to use this solution.
One of the big problems with using publically addressable IP (i.e., a client device connected to the public internet can sent a message directly to an internet protocol address of an IOT device that may be connected to a private network) relates to the limited number of IP addresses available for use relative to the increasing number of devices that connect to the Internet, and thus need a publicly addressable IP address. Internet Protocol version 4 (IPv4) has the ability to support a maximum number of 232 (4,294,967,296) unique IP addresses. By some accounts, address exhaustion occurred in 2011, and by other accounts, exhaustion will occur in 2015, or soon thereafter. Mobile networks in many countries have already started using Internet Protocol version 6, the successor protocol to IPv4. IPv6 uses a 128-bit address, thus allowing 2128 addresses. Unfortunately IPv4 and IPv6 are not designed to be interoperable, complicating the transition to IPv6 for both wireless devices as well as Internet systems. There are several IPv6 transition mechanisms to support interoperation, but there are no universal methods to bridge the networks. IPv6 essentially creates a parallel independent network requiring translator gateways that employ one of the transition mechanisms. In the past, some operators have offered (and may continue to do so) Subscriber Identity Modules (“SIM”) with fixed, public IPv4 addresses, but the added cost and limited availability of unassigned addresses eliminates using fixed IPv4 addresses as a serious solution for the high number IOT devices that experts forecast will be ‘Internet-connected’ in the coming years and decades.
With the large number of IOT devices and with the user expectation of Internet like responses from those devices, and the need for remotely controlling WWAN connected devices, it is desirable to have a reliable and high speed method to re-establish a data session with a devices that may have already ended a session, but that remains attached. It is desirable to minimize unnecessary data flow between WWAN connected remote-devices if the purpose of the data flow is merely to support ‘stay-in-contact’ polling messaging that is used to maintain a data session that otherwise isn't transferring data. It is also desirable to minimize power consumed by the communications radio of IOT devices for maintaining ‘stay-in-contact’ polling.